Date: Tue, 27 Jan 2004 12:30
From: Guillermo Stenborg
Subject: 'Full' Halo CME on 2004/01/26, probably backsided
Status: O
UCMEO 93001 40127 1730/
40126 61530 80242 0002/ 360// 223// 30829
///// ///// ///// ///// ///// 5//2/
99999
PLAIN
BT
LASCO/EIT observed a full halo CME on 2004/01/26. The event was
first observed in C2 at 15:30 UT as a bright loop front in the
SE with very faint extensions to SW. At 15:54 UT a second loop
front follows slightly N of the previous one with faint extensions
to NE. It cannot be said for sure whether the extensions to N
belong to the first of second loop front. Trailing material shaped
as a ragged front is first seen in C2 at 16:06 UT at a PA
coincident with that of the southern leg of the second loop front.
The first front is first seen in C3 at 16:18 UT. By 17:18 UT, C3
shows very faint but clearly discernible extensions above W, and
to a lesser extent above N, limbs. By 02:42 UT on next day the
event is no longer discernible in C3 fov.
The mean plane-of-sky speed measured at several PA on C3 data
resulted as follows:
785 km/s at PA ~203
829 km/s at PA ~155
250 km/s at PA ~55
As observed in EIT Fe XII running difference images, the activity
on the disk at the time of the event was minimal, which is
reflected in the corresponding GOES X-ray data.
The event has therefore been determined as a 'full' halo CME most
probably backsided.
Images and movies will shortly be made available at
ftp://ares.nrl.navy.mil/pub/lasco/halo/20040126
My apologies for the 1-day delay in reporting the event, but
Goddard was operating on 26th under 'Code Red' due to snow
and ice (i.e., non-emergency personnel are not to enter the Center).
Best wishes
Guillermo Stenborg
++
Dr. Guillermo A. Stenborg
SOHO-LASCO Operations Scientist,
CUA, MC 682.3, Bldg 26, Rm 001, F: +1-301-286-0264
NASA Goddard Space Flight Center,
Greenbelt, MD 20771. P: +1-301-286-2941
e-mail: stenborg@kreutz.nascom.nasa.gov
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